To be honest, PGR2 was the 'peak' of that game for me.. PGR3 wasn't half bad..
But PGR4 seemed to lose it for me, the career mode was a slog and being forced to do bikes seperately to cars was a chore I didn't enjoy at times..
It felt like the addition of weather and other 'fancy' but not totally necessary effects blunted the actual racing a little bit..
Blur needs a demo so we can see if it is any good or not, but it does have an element of MC:LA about it, with the 'power ups' whilst racing thing going on, and I'm ashamed to say I absolutely loved MC:LA as a single player experience..